Yagai play: Nozoki no nureba.

Minoru and Rina are treasure hunters who have pledged their future to each other. However, Rina loses her loved one and decides to return to her homeland of Japan on her own. However, she is pursued by the notorious Loco Moco couple, who are in the same business. Upon hearing that Rina has acquired a new treasure, they plot to steal it from her.